Providing a barrier layer for photoresist processing

Abstract

In certain embodiments, a method of microfabrication includes forming a layer stack on a wafer, the layer stack including a photoresist layer formed on an underlying layer. The method further includes depositing a barrier layer on the photoresist layer, the barrier layer selected to prevent penetration from one or more environmental components. The method further includes exposing the photoresist layer to a pattern of actinic radiation and developing the photoresist layer.

What is claimed is: 
     
         1 . A method of microfabrication, the method comprising:
 forming layer stack on a wafer, the layer stack including a photoresist layer formed on an underlying layer;   depositing a barrier layer on the photoresist layer, the barrier layer selected to prevent penetration from one or more environmental components;   exposing the photoresist layer to a pattern of actinic radiation; and   developing the photoresist layer.   
     
     
         2 . The method of  claim 1 , wherein the barrier layer is deposited prior to exposing the photoresist layer to the pattern of actinic radiation. 
     
     
         3 . The method of  claim 1 , wherein the barrier layer is deposited subsequent to exposing the photoresist layer to the pattern of actinic radiation. 
     
     
         4 . The method of  claim 1 , wherein the barrier layer is deposited using a spin-on deposition process. 
     
     
         5 . The method of  claim 1 , further comprising executing a post exposure bake, wherein the barrier layer is deposited prior to the post exposure bake. 
     
     
         6 . The method of  claim 1 , wherein the one or more environmental components include water vapor. 
     
     
         7 . The method of  claim 6 , wherein the barrier layer is selected to have a water vapor permeability of less than 3.5×10 −14  [g m m −2  s −1  Pa −1 ]. 
     
     
         8 . The method of  claim 1 , wherein the photoresist layer includes a metal-oxide photoresist that is deposited on the underlying layer using a spin-on deposition process. 
     
     
         9 . The method of  claim 1 , wherein developing the photoresist layer also removes the barrier layer. 
     
     
         10 . The method of  claim 1 , further comprising removing the barrier layer prior to developing the photoresist layer. 
     
     
         11 . The method of  claim 1 , wherein the underlying layer comprises multiple layers, the multiple layers being formed on a silicon substrate. 
     
     
         12 . A method of microfabrication, the method comprising:
 receiving a wafer to be patterned by photolithography;   selecting a photoresist formula including photoresist components and barrier layer components, the photoresist formula configured to self-segregate so that the barrier layer components separate vertically above the photoresist components;   depositing the photoresist formula on the wafer by spin-on deposition, the photoresist formula self-segregating into a photoresist layer underlying a barrier layer;   exposing the photoresist layer to a pattern of actinic radiation; and   developing the photoresist layer.   
     
     
         13 . The method of  claim 12 , further comprising executing a post exposure bake, wherein the barrier layer is deposited prior to the post exposure bake. 
     
     
         14 . The method of  claim 12 , wherein the barrier layer components are selected to prevent penetration from water vapor. 
     
     
         15 . The method of  claim 14 , wherein the barrier layer components are selected to have a water vapor permeability of less than 3.5×10 −14  [g m m −2  s −1  Pa −1 ]. 
     
     
         16 . The method of  claim 12 , wherein the photoresist components include a metal-oxide photoresist. 
     
     
         17 . A method of microfabrication, the method comprising:
 forming a layer stack on a wafer, the layer stack including a photoresist layer formed over one or more underlying layers;   depositing a barrier layer on the photoresist layer by vapor-phase deposition, the barrier layer selected to prevent penetration from one or more environmental components;   exposing the photoresist layer to a pattern of actinic radiation; and   developing the photoresist layer.   
     
     
         18 . The method of  claim 17 , wherein the barrier layer is deposited prior to exposing the photoresist layer to the pattern of actinic radiation. 
     
     
         19 . The method of  claim 17 , wherein the barrier layer is deposited subsequent to exposing the photoresist layer to the pattern of actinic radiation. 
     
     
         20 . The method of  claim 17 , wherein depositing the barrier layer on the photoresist layer by vapor-phase deposition and exposing the photoresist layer to the pattern of actinic radiation are performed in a vacuum.